Switch for submersible pump



May 24; 1960 A. v. WEBER v. 2,938,090

SWITCH FOR SUBMERSIBLE PUMP Filed June 17, 1959 FIGS 2a uvmvron BYANTHONY v. WEBER 15 gs Q02, ar /5L4 ATTORNEY 2,938,090 SWITCH FOR SUBMERSIBLE PUMP Filed June 17, 1959, Ser. No. 820,956 Claims. (Cl. 200-81 This invention relates in general to pumps and, more particularly, to control switches therefor.

' It is an object of the present invention to provide a control switch for a submersible pump as utilized in a well, tank, or the like, which is adapted for disposition within the body of fluid and operated for circuit control in response to the fluid pressure.

It is a further object of the present invention to provide a control switch for submersible pumps which is adapted for automatic circuit-closing action upon the developmentof a predetermined hydrostatic pressure and to be maintained in such condition until the pressure has been decreased to a preselected amount, whereupon said switch will effect circuit-opening.

It is an additional object of the present invention to provide a control switch for submersible pumps which is adapted for circuit-opening operation at a predetermined pressure of the surrounding fluid so that the level thereof will at all times be. above the intake of the pump and of such height as to provide suflicien't cooling therefor.

It is another object of the-present invention to provide a control switch for submersible pumps wherein the operation of the switch does not entail the development of heat with consequent gas production so that the switch will not be subjected to ultimate destruction through the creation of insuppressible gas pressures.

It is a still further objectof the present invention to pro-.

vide a control switch for submersible pumps which has a marked simplicity of parts; which may be most economically manufactured; which has proven reliable and durable in usage; and .which is so designed as to be readily installed withinthe relatively small diametered well casings currently used. 1

Other objects and details of the invention will'be apparent from the following description, when read in connection with the accompanying drawing, wherein- Figure 1 is a side view of a switch unit constructed in accordance with and embodying the present invention illustrating the samein operative position, mounted on a submersible pump discharge pipe.

Figure 2 is a horizontal transverse section taken on the line 2-2 of Figure 1.

Figure 3 is a vertical transverse section taken through the switch unit and showing the switch in circuit-open condition.

Figure 4 is a vertical line 44 of Figure 3. v

Figure 5 is a front view of the switch unit with the cover plate, diaphragm and pressure plate removed.

Figure 6 is a fragmentary vertical transverse section taken along substantially the same line as Figure 3 but showing the switch in circuit-closed condition.

Referring now by reference characters to the drawing which illustrates the preferred embodiment of the present invention, 1 designates a pump wellhaving a wall or casing 2' within which atits lower end is disposed a sub mer'siblc pump 3 connected to the lower end of a pipe transverse section taken on the discharge section 4; said latter being engaged at its upper end to a threaded fitting 5 formed at the lower end of the cast metallic body 6 of a control switch unit A. At the upper end of body 6 there is provided a similar fitting 5', aligned with fitting 5 for securement to the lower end of a pipe discharge section 7. Said body 6 of switch A is of parti-spherical shape having a vertical planar face 8 with an opening 9 therethrough for communication with the outer open end of a cylindrical chamber 10 extending transversely of body 6; the diameter or cross-section of said chamber 10'is less than the diameter upon which the spherical portion of body 6 is formed so that fluid passages 11 are provided between the outer face of chamber 10 and the inner face of the confronting portions of body 6' 4, 7. In'tegrally' for connecting discharge pipe sections formed on the side face 8 is an annular mounting rim 12 having substantially the same inside diameter asopening 9 and chamber 10. Secured, as by threading, within horizontally disposed, axially aligned tapped openings in the inner surface of mounting rim 12, adjacent the upper end thereof, are aligned pivot pins 13, 13' with their spaced apart, inner ends being received within bearings 14, 14', respectively, formed in spaced arms 15, 15', respectively, in the outer, upper end portion of member 16 which is thereby said pins 13, 13'.

Cradle member 16 is of being presented within chamber 10 for swingable movement therein within a vertical plane about its pivot axis, with its inner end terminating spacedly from the inner end wall of said chamber '10. Cradle 16 is designed and adapted for snugly and reliably receiving and maintaining the elongated, bullet-like body 17 of a mercury switch 18, the outer end of which is disposed inwardly of bearings 14, 14' and, hence, spacedly from the outer end surface of said cradle 16. Internally, switch 18. is provided adjacent its spaced contacts 19, 19' connected to leads 20, 20, re spectively, which pass outwardly, through suitable openings, in body 17, thence through cut-away sections 21, 21 respectively, in the sides of cradle 16 for projection rockably supported upon through openings in mounting rim 12 for ultimate integration within the electrical circuit for pump 3. The lower, outer portion of cradle 16, below cut-away sections '21,. 21,

I bias of the lower outer end portion of the coupled cradle 16 and mercury switch 18 about the eccentric pivot axisthereof, wherebysaid cradle 16 wardly rocked condition at its will be normally in down inner end with its lower,

3 outer end disposed outwardly of the pivot axis (Figure the contacts 19, 19' of as by a loop or hook, upon a support 25 extending out wardly from the central, outer lower face of cradle 16.

The upper end of spring 24 is fixed upon a pin 26 transversely disposed within an opening 27 drilled or otherwise J end, spring 24 will be stressed and, hence,

provided in the upper end of mounting rim with, and above, the spacing between arms is to be especially noted that with cradle 16 normal, outwardly rocked condition at its '12 aligned 15, 15. It being in its outer, lower resistant to applied force for rocking cradle 16 inwardly at its lower end. Accordingly, it will be observed that spring'zrt as thus stressed combines with the gravitational bias of thejoint cradle 16 and switch '18 so as to materially en-' hance the resistance of the latter against movement to a sleeve-type cradle,

general cylindrical character,

upper, outer end with a pair of is of-relatively increased thickness, as at. 23, for conducting to the outward and upward swinging cause the latter to be rocked upwardly at its inner end, and, hence, into circuit-closed condition. Spring 24 as presented under tension as above described will thus have its major axis inclined to the vertical and presented outwardly of the pivot axis of said cradle 16.

Presented within the opening of rim 12 and bearing against the forward face of cradle 16 is a circular, metallic pressure plate or actuator 28, having suitable recesses formed on its inner face for receiving projection 25 and spring 24 so that the same may abut cradle 16; said plate 28 having a diameter slightly less than the inside diameter of rim 12 for movement therein. Integral with rim 12 on its inner surf-ace and spaced inwardly from its outer, open end, is a circumferentially extending abutment 30 for detent-forming engagement with pressure plate 28 to limit the inward movement of the same. Due to the normal disposition of cradle 16, said pressure plate 28 in bearing against said cradle 16 will be presented in corresponding attitude with its upper portion inwardly of its lower portion and, hence, with its primary plane inclined to the vertical.

Outwardly of pressure plate 28, and in obscuring relationship thereto, there is provided a flexible diaphragm 31, as of rubber or the like, having a peripheral flange 32 suitably apertured for securement, as' by screws, to the outer face of rim 12. Said diaphragm 31 may be provided with a central crown portion 33 for increased resiliency thereof. Outwardly and spacedly from diaphragm 31 is a cover plate 34, having a plurality of perforations or apertures 35 in its central portion and being provided with a skirt 36 for secured disposition upon the peripheral surface of mounting rim 12 as by customary retaining means; said skirt 36 having a pair of bored radial projections 37, 37' for passage therethrough of leads 20, A gasket 38 is wedgingly engaged between the inner end face of cover plate 34 and the adjacent portion of side face 8 for development of a fluidtight seal.

In usage, switch unit A will be installed within a well casing, as shown in Figure l, and with leads 20, 20' being integrated within the electrical circuit for the pump 3 so that upon closure of contacts 19, 19' pump 3 will be actuated and, upon opening of said contacts, the said pump will be de-energized. It should be noted that the maximum cross-sectional extent of said unit A is less than the diameter of easing 2, which is customarily in the nature of 4 inches, so that said unit is designed for installation within current well constructions. With said unit A thus submerged within the fluid in well 1, the pressure of such fluid will act against diaphragm 31 and pressure plate 28. When the level of the fluid in well 1 has reached a point so as to develop a pressure head of predetermined amount, the pressure acting against diaphragm 31 and pressure plate 28 will overcome the combined resistance of the stressed spring 24 and the gravitational bias of cradle 16 with switch 18 so as to effect inward and upward swinging movement of cradle 16 about its lower, forward end, into the position shown in Figure 6, wherein mercury M will cover contacts 19, 19 and the circuit to pump 3 will be closed so that actuation of the same will be initiated. Pump 3 will continue to operate as long as switch 18 remains in such attitude so that the continued pressure against cradle 16 must be adequate to counter its gravitational bias. With pump 3 operating, the level of the fluid in well 1 will expectedly lower with corresponding decrease in the hydrostatic pressure thereof. When the fluid pressure has been decreased to an amount insuflicient to counter the gravitational bias of cradle 16, the latter will return to its normally outwardly rocked position at its lower end with consequent clearance of contacts 19, 19', so that pump operation will be discontinued. This condition will be maintained until the pressure in well 1 has once again risento a. value suflicient for overcoming spring 24 and the gravitational bias of cradle 16 for bringing about circuit closure and pump operation. Thus, the switch of the present invention will act automatically to cause pump operation when the hydrostatic pressure has reached a predetermined amount and to maintain the pump in operation until the pressure has been reduced to a preselected point, at which juncture the pump will be temporarily shut-down. Therefore, the above described cycle will be continuous without the intervention of extraneous expedients or human controlling action.

Spring 24 in being forced inwardly in its lower end portion through the applied fluid pressure will be caused to move through its center and thence into a position wherein its vertical axis will cross the pivot axis of cradle 16. In this latter position, wherein cradle 16 will be in circuit-closing disposition, said spring will exercise substantially no leverage so that the pressure required to maintain cradle 16 in such position will be only that requisite to overcome the gravitational bias of cradle 16 together with switch 18. It can' be readily seen that such pressure will be considerably less than that amount necessary for initially overcoming the stressed spring 24 together with the gravitational bias of said cradle 16 and switch 18. Accordingly, switch 18 will not be presented in circuit-closing condition until a relatively elevated fluid pressure has been applied, which may be in the order of 8 pounds per square inch. However, as the cradle 16 is thus caused to be moved into circuit-closed condition a markedly diminished pressure will be necessary to maintain suchcondition, and such may be in the neighborhood of one pound per square inch. Thus, it will be seen that pump 3 may be maintained in operating; condition while the hydrostatic pressure is being reduced from a relatively high value to a considerably lower amount which, in accordance with the example given, may be from 8 pounds per square inch to one pound per square inch.

In view of the foregoing, it will be seen that the unique coaction between spring 24 and cradle 16 will produce a predetermined pressure differential through which the pump may be continued in operation. The limits of such range may be selected and obtained by utilization of an appropriate spring with the novel cradle and it's eccentric pivoted mounting.

From the above, it is patent that the switch of the present invention will act automatically and that its circuit-closing operation will not be accompanied by the development of heat with consequent gas production, as has beenocca'sioned with consistent regularity in switches of the snap-acting type. The present switch may be most economically manufactured and having a simplicity of parts is not subject to breakdown but will operate for substantially indefinite periods without servicing so that considerable relative savings may be effected through usage. I v

It should be understood that changes and modifications in the form, construction, arrangement, and combinaiton of the several parts of the switch for submersible pump may be made and substituted for those herein shown and described without departing from the nature and principle of the present invention.

Having thus described my invention, what I claim and desire to secure by letters patent is:

1. A control switch for use with submersible pumps comprising a body for disposition within a fluid-containing vessel, said body having a chamber open at one end, a cradle member disposed in said chamber and being eccentrically, rockably mounted in its upper, outer portion, a mercury switch member being carried in said cradle for rockable movement therewith, saidcradle together with the switch carried thereby being gravitationally biased through the eccentric mounting into downward rocked position in their inner end portions presenting said switch incircuit'open condition, a resilent member fixed at its upper end on said body and at its lower end-to the lower outer face of said cradle, said resilient member being axially inclined to the vertical and extending forwardly of the pivot axis of said cradle and switch, and fluid-pressure responsive means provided in said chamber opening and connected to said cradle, whereby upon application of inwardly directed fluid pressure against said means such pressure will be resisted until the force of the spring and the gravitational bias of said cradle and switch are overcome, with consequent inward, upward swinging of the inner portion of said cradle and switch and causing said spring to move across center for presenting said switch in circuit-closed condition, whereby the force of maintaining said switch in circuit-closed condition will be less than the force required for causing same to move into the said circuit-closed condition.

2. A control switch as described in claim 1 and further characterized by the resilient member being a coiled, extension spring which latter in moving across center will move across and inwardly of the pivot axis of the cradle and switch.

3. A control switch as described in claim 1 and further characterized by said fluid-pressure responsive means comprising a pressure plate disposed abuttingly on its mner face against the outer face of said cradle, and a flexible diaphragm disposed across and outwardly of the pressure plate and the outer, open end of said chamber to seal same.

4. A control switch as described in claim 3 and further characterized by the provision of a detent within the chamber opening for limiting the inward movement of said pressure plate.

5. A control switch as described in claim 1 and further characterized by the rockable mounting for said cradle comprising a pair of axially aligned pivot pins being spacedly separated at their inner ends, and said resilient member being presented for presentation between said spaced apart inner ends of the pivot pins when said switch has been rocked into circuit-closed condition.

References Cited in the file of this patent UNITED STATES PATENTS 1,719,851 Raney July 9, 1929 1,854,540 Carlson Apr. 19, 1932 2,583,077 Arney Jan. 22, 1952 2,730,591 Nielsen Jan. 10, 1956 2,844,678 Nielsen July 22, 1958 

